Citrus Fruits Lab By: Evan

Problem/Question

What citrus fruit can produce the most power if it is made into a battery and why?


Ideas or Theories


Theory 1: Because battery acid has a very low PH, the best battery would be the lemon because it's PH should be the closest to the battery acid
Theory 2: Because batteries are in closed metal containers, the best battery would be the banana because it has a skin unlike all the other fruits
Theory 3: The higher the density would mean the fruit has more matter and therefore be able to produce more electricity because of the ions it has.

Plan

What we planned to do was to create multiple batteries out of these fruits and to measure which one was the most effective. In our class investigation on batteries, we learned not only how to create these bateries using salt water and two different electrodes. We wanted to do this experiment because we were interested in the battery investigation on voltaic batteries and we wanted to learn more about them. We were interested when we learned that you can create a battery so simply and we wanted to try it on organic material.

Hypothesis

I believe that a lemon will produce the most fruit because I know that it contains a lot of citric acid that can be used to form a battery. I have already witnessed a lemon battery and have seen them power small things. The acidity of this fruit may be a reason why it is such a successful battery. When batteries are made from citrus fruits, a lemon is usually the most common and therefore I believe it will produce the most power.

Materials

  • Cutting board

  • Knife

  • Fruits

  • Multimeter

  • Measuring scale

  • Popcorn bowl or large beaker

  • Fruit squeezer (you can use a clamp to squeeze)

  • Ph measurer

  • Two electrodes

  • Cardboard

Procedure

Lab 1

  1. Slice each individual fruit enough to get one individual piece of that fruit to weigh as close to 50g as possible (Keep sliced fruits)

  2. Create a holder for the metal electrodes(cardboard) you will stick into the battery so that the distance between each electrode is 1 or 2 cm

  3. Connect your electrode to your multimeter using aligator clips

  4. Stick the electodes into each 50 g piece of fruit and record the voltage and current

Lab 2

  1. Squeeze each fruits until you get 10 ml of liquid (store each liquid in a beaker)

  2. Record the PH of each liquid

  3. Measure the voltage and current of each liquid battery using the electrodes and the multimeter from Lab 1

  4. Record observations



Independent Variables

==

  • Weight of portion of fruit being tested
  • Distance alligator clips are apart
  • Volume of Juice
  • The electrodes
==


Background Research

Citric Acid

Citric Acid is a weak acid that is found in citrus fruits, usually, the more citric acid the more sour the fruit is. Fruits such as lemon and limes have a high concentration of this acid. It's chemical formula is C6H8O7 (carbon7,hydrogen8,oxigen7) and it looks like fine white powder at room temperature. It was discovered by alchemist Jabir Ibn Hayyan (Geber) in the 8th century.

Citrus Fruits

Citrus fruits are common in the household today. They are a very good source of vitamin C and contain citric acid. In the 18th century, a surgeon in the UK discovered that by eating these fruits, you could prevent scurvy. Eating these fruits make you much healthier and give you many vitamins and fibres.

Electrolyte

Electrolyte is a scientific name for salts and ions. It means that an ion is charged and is able to transfer electricity to a positive or negative electrode. Electolytes are found most commonly in some drinks and it is a name for the ion. In a lemon battery, electrolytes are used to transfer power.

Ion

Ion's are atoms that have lost one positive or negative electron giving them a positive or negative charge. In order for electricity to flow, you need to have enough ion's that are charged enough to pass on electrons. The amount of power is determined by the type of ion or the amount.

Results

Quantitative Data/ Observations

Fruit Juice

|| Fruits || Volts || Current || Weight (g) || || Orange || 0.50 || 0.26 || 273.76 || || Tangerine || 0.51 || 0.26 || 98.04 || || Lemon || 0.55 || 0.87 || 121.15 || || Lime || 0.51 || 0.13 || 93.07 || || Grapefruit || 0.54 || 0.55 || 286.10 || || Pear || 0.51 || 0.30 || 133.31 || || Banana || 0.55 || 0.21 || 170.85 || || Apple || 0.52 || 0.29 || 204.16 || ||~ Solid Form of Fruits ||

|| Fruits || Volts || Current || || Orange || 0.57 || 0.11 || || Tangerine || 0.54 || 0.06 || || Lemon || 0.47 || 0.31 || || Lime || 0.51 || 0.14 || || Grapefruit || 0.52 || 0.11 || || Pear || 0.52 || 0.06 || || Banana || 0.59 || 0.27 || || Apple || 0.58 || 0.05 ||

fruit_graph.JPG

fruit_juice_graph.JPG

Qualitative data/ observations

  • Measuring current and voltage is not definite, it changes rapidly
  • Our batteries were not very powerfull
  • Our fruit dried up on the table making juice very hard to get
  • Our results were around the same in voltage
  • Current seemed to be a greater difference


What I learned about science


What I learned about science from doing this lab was that batteries can be made from non organic and organic materials. I also learned that current can be extremely different from voltage and hard to measure. I realized that you can produce electricity because of the citric acid inside the fruits and the ions inside the fruits that enable you to create a battery. I realized that at the end of my experiment that the lemon makes the best battery because it always had the highest current and it had the highest voltage when we made the juice. One interesting observation was that the lemon had the lowest voltage out of all the solid fruit forms. We also noticed that the banana was the second best battery when it doesn't have as much citric acid as say a lemon or lime. I believe that this is because when we were testing we never washed the electrodes clean and so there still may have been lemon atoms on the electrode in the lime that would have altered our results. From this I learned that the materials you use must be the same as when you began your experiment. What I leaned about experimental work was that it is very difficult to prove a theory to be absolutely true. I also learned that it is important to clean and to make sure the materials I used to test with are completely clean and fresh. Next time I will test on just one material and put it through different conditions because I would be more likely to get better results and to learn more. The lab that we did has already been done and we knew that it would work. This experiment helped my understanding of the atomic theory of matter because I found out that the more electricity generated by a battery would be related to the amount of ion's inside each material. We also learned that it is the citric acid that has these ion's which makes it possible for electricity to be generated.

Figures



ions.gif
This image demonstrates ion's and how they look atomically. The ion's are what helps the electrons get transfered between each electrode.

ph_scale.jpg
This picture shows the PH scale and some citrus fruits may be on it, Ph may be a good indicator of the best battery. Battery acid has a low PH which might be important.

ladis.gif
This picture shows an example of salt dissolved into a solution of water and a battery made from it.



Picture_005.jpg
This is our class making a battery with salt water, the ions in the salt water create electricity whereas there is no ions in normal water.


Picture_100.jpg
This is a picture of us trying to break open a battery to see if we could get some acid. We could find no acid but we found numerous cells.

untitled.JPG
This is the atomic structure of a citric acid molecule, there appears to be two connections to every oxygen atom that isn't connected to a hydrogen atom

Sources

http://www.hilaroad.com/camp/projects/lemon/lemon_battery.html
http://hyperphysics.phy-astr.gsu.edu/hbase/chemical/electrochem.html
http://hyperphysics.phy-astr.gsu.edu/hbase/electric/battery.html#c1
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http://www.readersdigest.com.ph/rd/rdhtml/en/communities/food_cat.jsp?mccid=11&ccid=91
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Mr. Happer